Magnum

Some rifle and pistol cartridges might be referred to as a "magnum." Depending on the cartridge design, it may referring to the powder charge or the case design.

A .357 Magnum cartridge was developed from the .38 Special case. Its case length is slightly longer. Due to the longer case, the .357 Magnum will hold more powder than a .38 Special. A bullet from a .357 Magnum will travel much faster and have a greater force of impact than the same bullet fired from a .38 Special. This is why it is called a magnum cartridge. Firearms that use magnum ammunition may also be called magnum.

An instructor hands you a 300 Winchester Magnum and a 300 Savage case. Without looking at the base of the case can you tell which case is the 300 Win Mag? In this example, the word "Magmun" refers to a belted case design cartridge. Which case is the belted case?